The present invention relates to an apparatus for determining the surface roughness of a material.
A conventional method of determining the surface roughness of a material uses a probe which has a stylus. The probe is moved relative to the material and the stylus makes contact with and moves over the surface of the material. As the stylus moves over the surface of the material, displacements of the stylus are transferred directly as stresses or strains to a sensitive element in the probe. This method has several drawbacks such as the relative speed of movement between the stylus and the material must be sufficiently low so that surface irregularities may be resolved. Furthermore the stylus must have a fine point in order for it to ride up and down the surface irregularities, giving rise to the possibility of tearing relatively thin sheet materials. This principle of determining surface roughness requires a compromise to be made between sensitivity and ruggedness.